In recent years, there has developed a noticeable upward trend in the number of people who are devoting a significant amount of time to recreational pursuits of one type or another. One of these recreational pursuits is that of motorcycling. The extent of interest which exists in motorcycling is clearly shown by the rapidly increasing number of registrations of this type of motor vehicle. There are a variety of ways in which motorcycles are being used. Namely, some people employ motorcycles merely as a recreational vehicle. Others are interested in participating in the various racing events for motorcycles which are held in large numbers particularly during the summer months in different portions of the country. In addition, many organizations which are involved in public safety such as police departments, etc. have purchased motorcycles for their own use as a means of assisting them to fulfill their assigned responsibilities. Finally, recently when the gasoline shortage became pronounced throughout this country, many people turned to motorcycles as an alternate mode of transportation to get to and from work, etc. because of the fact that motorcycles are noted for their economical fuel performance.
Concomitant with the rise in interest paid to motorcycles, there has been some attention given to making changes in the nature of the construction of the motorcycles. This has led to a proliferation of different types of motorcycles as well as to the many different models of each type which are presently being marketed. As a result, the potential purchaser of a motorcycle has practically an unlimited selection to choose from. In addition to the so-called original equipment manufacturers who manufacture and sell motorcycles as complete units, there also exists a number of other manufacturers who specialize in the manufacture only of different ones of the major components which are embodied in a motorcycle. The latter manufacturers offer their products to potential purchasers as components which can be substituted in the motorcycle for original equipment components provided therein. As a result of the availability of the latter type of products, a motorcycle owner by purchasing such equipment and embodying it in his motorcycle is capable often of changing almost completely the entire character of his motorcycle.
Notwithstanding the fact that some changes have been made in the construction of motorcycles here to date, by and large these changes have been in the nature of matters of appearance rather than in matters of structure. More specifically, apart from notable advances which have been made in recent years in the construction of motorcycle seats, little has changed heretofore in the basic design of motorcycles from a structural standpoint.
However, because of the continuing high price of gasoline and because internal combustion engines are known to produce exhaust products that are deleterious to the environment, there has been some interest exhibited in providing a motorcycle which would be powered by some means other than an internal combustion engine. In this regard, one such alternative power source for the conventional gasoline powered motorcycle is a motorcycle powered by electricity. To this end, there has now been produced and there is presently being commercially marketed an electric motorcycle which embodies an electric motor which in turn is connected in electrical circuit relation with a multiplicity of rechargeable storage batteries.
In providing an electrically powered motorcycle, there are a number of design considerations which must be borne in mind. Most notably, consideration must be given to providing means operable for purposes of effecting control over the operation of the aforementioned electric motor. More specifically, a need exists to be able to adjust the speed of the motorcycle. Also, there is a need to be able to adjust the rate of acceleration and deceleration thereof as well as to enable the motorcycle to cruise at any speed within the motorcycle's capability.
Heretofore, for purposes of effecting the desired control over the operation of the electric motor, contactors and solid-state devices have been utilized in an attempt to make the electrically powered motor vehicle function smoothly. However, the use of such devices in this connection has not proven to be entirely satisfactory. Namely, when components which are selected based on their cost are emloyed in the aforedescribed connection thereby providing a control system which may be characterized as an economical one, most commonly the result is found to be that the desired smoothness of operation is lacking, i.e., what may be referred to as a jolty electrical vehicle is provided. On the other hand, when sophisticated solid-state controls are used, the cost of providing the control system is relatively large and thus increases the price of the motor vehicle to such a high level as to price the motor vehicle out of the reach of most of the potential customers therefor.
Thus, notwithstanding the fact that there have existed control systems capable of being embodied in electrically powered motor vehicles, there has nevertheless been evidenced a need to provide a new and improved control means operable for effecting control over the electric motor of an electrically powered motor vehicle. More specifically, although a number of control systems have been provided heretofore, none of them have proven to be entirely satisfactory when placed in operation. By and large, this has been because such prior art forms of control systems when applied to electrically powered motor vehicles have been characterized by the fact that they either are incapable of providing the desired smoothness of operation or else they require the interpositioning of an unnecessary amount of control devices between the electrical motor and the batteries which provide the power thereto.
Accordingly, it is an object of the present invention to provide such a control system which obviates the necessity of utilizing a multiplicity of control devices interposed between the electric motor and the batteries, while yet being operable to effect good speed control for electrically powered motor vehicles.
It is another object of the present invention to provide such a control system which is particularly suited for employment for purposes of effecting control over the electric motor embodied in an electrically powered motor vehicle which is operable therein as the prime mover thereof.
A further object of the present invention is to provide such a control system which is characterized in that it is capable of being easily maintained and repaired by ordinarily trained electricians.
A still further object of the present invention is to provide such a control system which is readily capable of being economically mass produced by motor manufacturers without requiring any technical breakthroughs to be achieved by the latter in order to do so.
Yet an object of the present invention is to provide such a control system which is readily adapted through the performance of minor modifications thereto of being utilized in a variety of different applications.
Yet another object of the present invention is to provide such a control system which is relatively inexpensive to manufacture and therefore is effective to assist in maintaining the cost of manufacture of the electrically powered motor vehicle which embodies the subject control system at a relatively low level.